The overall objective of this subproject is to evaluate the effect of fetal growth aberration on postnatal growth and development. The goal is to investigate the development of childhood obesity and its relationship to blood pressure, glycemia, insulinemia and cognitive, motor and activity patterns from birth to seven years of age in macrosomic infants of gestational diabetic mothers (IGDM). Two groups of infants will be enrolled. Cohort #1 will consist of infants born between July 1, 1991 through December 30, 1992. These infants will be followed prospectively for three years. Cohort #2 will consist of infants born July 1, 1987 and December 30, 1988 who will be four years old when this grant begins and they will be studied through seven years of age. The subjects will be further divided into macrosomic and non-macrosomic groups born to GDM and non-GDM. Therefore, the two cohorts will compromise a group of children born to gestational diabetic and control mothers who will be followed longitudinally through seven years of age. The data to be collected include anthropometric measurements, skinfold thickness, glucose level, insulin level, blood pressure measurements, developmental test scores and activity levels. The data will be analyzed to evaluate the effect of macrosomia in infants born to GDM with reference to development of obesity during childhood and its contribution to abnormalities in glucose metabolism, hypertension, cognitive function, motor skills and activity level.